Projection mapping is a light manipulation technology that employs standard image projectors to display two-dimensional (2D) and/or three-dimensional (3D) images onto flat and/or irregularly-shaped display surfaces. Common projection mapping solutions designed to extend an image over a wide display space (referred herein as extended scene generation) typically employ multiple projectors controlled by specialized software and other technologies configured to warp and blend the projectors' outputs to seamlessly assemble a continuous, extended image across the desired area of the display space.
The display quality of a projection mapping implementation depends largely on the quality of the projectors used. Digitized image content is made up of a large number of individual points of light called “pixels.” The more pixels a projector is capable of directing into a targeted display space, the more image detail will be perceptible in that display space. Resolution is the level of clarity that is achieved in a projected image. If a projection mapping solution employs a low-resolution projector, the result is enlarged pixels that the equipment is unable to project as densely into the display space boundary (i.e., resolution suffers).
The distance between a projector and a target image (also referred to herein as a target FOV) is another crucial element in achieving high-resolution projection mapping. In general, the greater the distance between the fixed-focus projector and a FOV, the larger the projected image will appear. However, image quality will be impacted as defined by the Inverse-Square Law which holds that the luminosity decreases in intensity the further a light beam must travel. In other words, the greater the throw distance, the less bright the display of the image upon the FOV will be.
One type of device employed in projection mapping is a spatial light modulator (SLM). Operation of an SLM involves imposition of some form of spatially-varying modulation on a projected beam of light. For example, SLM designs exist that modulate either the phase of a beam or both the beam intensity and the phase simultaneously. By using specialized software to drive such modulation, a two- or three-dimensional image may be spatially mapped on a virtual program which mimics the real environment upon which the image is to be projected. The software interacts with such a modulation device to fit a desired image onto the surface of a target FOV. This modulation technique may be used to add extra dimensions, optical illusions, and notions of movement onto previously static objects. However, as is the case with other projection solution types, wide FOV projection quality for systems that employ SLMs is limited by equipment performance characteristics and distance to target FOV.
Common methods of extended scene generation include the following: 1) direct projection into a perceiving device (such as a camera, eye, sensor, or specimen), and 2) projection onto an intermediate screen that diffusely reflects or transmits the light. Movie theaters utilize the latter format with a diffuser screen. Both methods are limited in the trade space that exists between angular resolution and FOV, the limiter being the number of pixels available in the SLM(s) used. For directly projected scenes, the problem of designing for extended scene generation reduces to a) providing more pixels through a common optical projection lens system, and b) providing the number of pixels without prohibitive cost. For projection onto an intermediate screen, in most cases the problem reduces to the cost element only. In the current state of the practice, high-performance projection equipment (e.g., infrared SLMs with associated projection lenses) can be prohibitively expensive for many consumers.
What is needed in the industry is an image projection solution for generation of large field of view (FOV) scenes at resolutions that rival the quality of common projection mapping solutions, but which employ a single SLM or similar projection component to reduce design cost.